Oakes Irrigation Research Site
Carrington Research Extension Center * North Dakota State University
P.O. Box 531, Oakes, ND 58474-0531, Phone: (701) 742-2744, FAX: (701) 742-2700, E-mail:										Kelly.c.Cooper@ndsu.edu
Strip-Till, Corn on Soybean, Nitrogen Rate Study
K. Cooper, L. Besemann and H. Eslinger
The objective of this study was to compare corn yields of a corn/soybean rotation to those in a companion corn/corn rotation and to find differences in N response and other agronomic measurements in no-till rotations, utilizing strip-till.
MATERIALS AND METHODS
Soil:	Embden loam and Gardena sandy loam; pH = 7.4; 2.6% organic matter; Soil N average was 11 lbs/acre; soil P and soil K were very high; soil S was very low.
Previous crop:	2016 – soybean.
Seedbed preparation:	Strip-till May 5 with an Orthman strip-till machine.
Hybrid:	Pioneer 9929 AMXT.
Planting:	Planted May 9 @ 33,000 seeds per acre in 30-inch rows.
Plots:	Plots were 40 ft long by 15 ft (6 rows) wide.  There were four replications.
Fertilizer:	All plots received (via stream-bar) 10 lbs N/acre and 40 lbs P2O5/acre as 10-34-0; 15 lbs N/acre and 20 lbs S/acre as 15-0-0-20 May 22.  Stream-barred 73 lbs N/acre as 28-0-0 to the 100 lb treatment and 40 lbs N/acre as 28-0-0 to the 100d, 150 and 200 lb treatments May 25.  Sidedress N treatments as 28-0-0 (three inches deep) June 16; the 100d treatment received 35 lbs N/acre, the 150 lb treatment received 83 lbs N/acre and 200 lb treatment received 133 lbs N/acre.
Irrigation:	Overhead sprinkler irrigation as needed.
Pest control:	Roundup (32 oz/acre) + AMS (10 lb/100gal) + NIS (1 pt/100 gal) + Laudis (3 oz/acre) + Attrex 9-0 (0.5 lb ai/acre) May 26.
Remote sensing:	Opti-Sciences CCM 200 Plus chlorophyll meter.
Harvest:	Hand harvested October 24.  Harvest area was the two center rows from each plot (72 feet of total row).
RESULTS
Determining nitrogen sufficiency in time is important to achieve N efficiency.  Remote sensing utilized an Opti-Science CCM 200 chlorophyll meter determine N sufficiency.  Increasing nitrogen rates (N) increased grain yield and chlorophyll meter readings.  Remote sensing with the chlorophyll meter did well in predicting corn N status.
Table 1.  Strip-till, corn on soybean nitrogen rate study at the Oakes Irrigation Research Site in 2017.
		Grain			Chlorophyll
Fertilizer	Grain	Yield	Harvest	Test	Meter	Nitrate-N		Seed	Seed	Seed	Emerge	Silk
N Rate	Yield1	2009-17	Moisture	Weight	Reading2	Stalk	Fall Soil	Protein	Oil	Starch	Date	Date	Population
lb/acre	bu/ac	bu/ac	%	lb/bu	7-Aug	ppm	lbs/ac	----------%-----------					plants/ac
22	175.3	135.8	19.9	55.8	41.4	12	14	3.2	7.5	73.4	25-May	21-Jul	39263
100d	253.6	198.6	19.3	56.3	45.9	59	12	3.2	8.1	72.9	25-May	20-Jul	39852
100	258.9	194.1	19.6	56.2	52.4	41	12	3.2	8.3	72.8	25-May	19-Jul	39263
150	265.5	228.2	19.8	56.3	52.5	182	18	3.1	8.4	72.9	25-May	20-Jul	39498
200	266.7	236.4	19.8	56.2	54.9	163	27	3.3	8.6	72.5	25-May	20-Jul	38969
Mean	244.0	--	19.7	56.2	49.4	91	17	3.2	8.2	72.9	25-May	20-Jul	39369
C.V. %	4.7	--	1.7	0.8	22.0	61	60	6.1	2.5	0.6	0	0	2.1
LSD 0.10	14.4	--	0.4	0.6	13.7	70	12	NS	0.26	0.6	NS	0.7	NS
LSD 0.05	17.6	--	0.5	0.7	16.7	85	15	NS	0.32	0.7	NS	0.9	NS
Planting Date = May 9; Harvest Date = November 1; Previous Crop = Soybean
1 Yield adjusted to 15.5% moisture.
2 Opti-Science CCM 200.
Oakes Irrigation Research Site									Other corn Studies
Variety trials	Crop index			Home page		Report 2017			Corn hybrid performance trial – irrigated
									Corn hybrid performance trial – dryland
									Stover removal corn/corn and corn/soybean rotation
									Strip-tilled corn N rate; corn corn rotation